How to Replace a Flat Roof Flashing

If you notice a damp spot on the ceiling or a persistent drip during or after rainfall, you may have a leak in your flat roof flashing. The flashings are strips that connect different components of the flat roof. If they become damaged or loose, water can seep through the space left in between the flashing and the piece of the roof that it attaches to. The water then continues to filter through the layers of the flat roof until it makes its way to the ceiling inside of the home.

Step 1 - Gather Your Materials

Before you begin working on a flat roof flashing repair, gather the following materials:

  • Flat roof repair kit, available at hardware and roofing stores
  • Fungicide
  • Ladder
  • Craft knife
  • Adhesive

Prior to stepping onto the roof or putting any weight on it whatsoever, it's crucial that you determine the sturdiness of your flat roof. And old or damaged roof may break under the weight of a person or even of some of the equipment listed above, and you can cause serious damage to your home as well as injury to yourself in the process. If you have any doubts, hire a roofing professional to examine the roof for signs of structural damage.

Step 2 - Locate the Source of the Leak

If there is a wet spot on the ceiling in your home or a water drip at a certain location, take note of that spot. While it is possible that the surface roof leak is located in that exact position, it is more likely that the water entered the roofing layers at a different point and seeped through the roof by making its way down any slight incline or gradiant.

Begin by examining the site of the leak itself for signs of surface damage. From there, move up the slope of the roof or determine which way water would naturally flow on the roof. Check along this path until you find a blister, bubble or other sign of damage to the flat roof flashing.

Step 3 - Fix the Source of the Leak

If the damage to the roof flashing was due to fungus growth, use the fungicide to eliminate the problem. If this is the case, be careful to utilize the appropriate safety equipment, and be prepared to make additional fungicide treatments in the future if the growth returns.

If you detect a bubble or blister in the roof flashing, carefully cut into it with your craft knife. You'll need to use the flashing repair kit to seal up any damages that have occurred. Follow the instructions on the repair kit for the best results, and be sure to allow adequate time for any adhesive or other repair material to dry. If there is a chance that the roof might be rained on while the flashing is drying, cover it with a tarp to avoid any further damage.

If the problem is more extensive than this, or if you have any concerns about your ability to repair your flat roof flashing, consult with a roofing professional.